Gremlin server with neo4j - neo4j

Question

I am trying to use gremlin-server by tinkerpop. I am not able to launch a gremlin server with neo4j.
The documentation says.
Note that TinkerPop does not include Neo4j dependencies in its distributions. To use this file, please ensure that Neo4j dependencies are installed into Gremlin Server's path with gremlin-server.sh -i org.apache.tinkerpop neo4j-gremlin 3.y.z
I have already installed the neo4j-gremlin using :install, as -i is said to be deprecated.
Still, I am getting the following error, on the following command
.\bin\gremlin-server.bat .\conf\gremlin-server-neo4j.yaml
ERROR
[WARN] DefaultGraphManager - Graph [graph] configured at [conf/neo4j-empty.properties] could not be instantiated and will not be available in Gremlin Server. GraphFactory message: GraphFactory could not find [org.apache.tinkerpop.gremlin.neo4j.structure.Neo4jGraph] - Ensure that the jar is in the classpath
java.lang.RuntimeException: GraphFactory could not find [org.apache.tinkerpop.gremlin.neo4j.structure.Neo4jGraph] - Ensure that the jar is in the classpath
at org.apache.tinkerpop.gremlin.structure.util.GraphFactory.open(GraphFactory.java:63)
at org.apache.tinkerpop.gremlin.structure.util.GraphFactory.open(GraphFactory.java:104)
at org.apache.tinkerpop.gremlin.server.util.DefaultGraphManager.lambda$new$0(DefaultGraphManager.java:57)
at java.util.LinkedHashMap$LinkedEntrySet.forEach(Unknown Source)
at org.apache.tinkerpop.gremlin.server.util.DefaultGraphManager.<init>(DefaultGraphManager.java:55)
at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
at sun.reflect.NativeConstructorAccessorImpl.newInstance(Unknown Source)
at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(Unknown Source)
at java.lang.reflect.Constructor.newInstance(Unknown Source)
at org.apache.tinkerpop.gremlin.server.util.ServerGremlinExecutor.<init>(ServerGremlinExecutor.java:105)
at org.apache.tinkerpop.gremlin.server.util.ServerGremlinExecutor.<init>(ServerGremlinExecutor.java:84)
at org.apache.tinkerpop.gremlin.server.GremlinServer.<init>(GremlinServer.java:111)
at org.apache.tinkerpop.gremlin.server.GremlinServer.main(GremlinServer.java:355)
[INFO] ServerGremlinExecutor - Initialized Gremlin thread pool. Threads in pool named with pattern gremlin-*
Exception in thread "main" java.lang.IllegalStateException: java.lang.ClassNotFoundException: org.apache.tinkerpop.gremlin.neo4j.jsr223.Neo4jGremlinPlugin
at org.apache.tinkerpop.gremlin.groovy.engine.GremlinExecutor.initializeGremlinScriptEngineManager(GremlinExecutor.java:444)
at org.apache.tinkerpop.gremlin.groovy.engine.GremlinExecutor.<init>(GremlinExecutor.java:103)
at org.apache.tinkerpop.gremlin.groovy.engine.GremlinExecutor.<init>(GremlinExecutor.java:72)
at org.apache.tinkerpop.gremlin.groovy.engine.GremlinExecutor$Builder.create(GremlinExecutor.java:586)
at org.apache.tinkerpop.gremlin.server.util.ServerGremlinExecutor.<init>(ServerGremlinExecutor.java:157)
at org.apache.tinkerpop.gremlin.server.util.ServerGremlinExecutor.<init>(ServerGremlinExecutor.java:84)
at org.apache.tinkerpop.gremlin.server.GremlinServer.<init>(GremlinServer.java:111)
at org.apache.tinkerpop.gremlin.server.GremlinServer.main(GremlinServer.java:355)
Caused by: java.lang.ClassNotFoundException: org.apache.tinkerpop.gremlin.neo4j.jsr223.Neo4jGremlinPlugin
at java.net.URLClassLoader.findClass(Unknown Source)
at java.lang.ClassLoader.loadClass(Unknown Source)
at sun.misc.Launcher$AppClassLoader.loadClass(Unknown Source)
at java.lang.ClassLoader.loadClass(Unknown Source)
at java.lang.Class.forName0(Native Method)
at java.lang.Class.forName(Unknown Source)
at org.apache.tinkerpop.gremlin.groovy.engine.GremlinExecutor.initializeGremlinScriptEngineManager(GremlinExecutor.java:407)
... 7 more

Answer 1

:install is the console command.
install is the server command. -i also still works.

Answer 2

As a committer of the gremlin-python-tutorial github project my answer would be to look at the relevant lines of the
https://github.com/WolfgangFahl/gremlin-python-tutorial/blob/master/run
script.
version=3.4.3
plugin=neo4j-gremlin
gsd=apache-tinkerpop-gremlin-server-${version}
if [ ! -d $gsd/ext/$plugin ]
then
color_msg $blue "installing plugin $plugin"
$gsd/bin/gremlin-server.sh install org.apache.tinkerpop $plugin $version
else
color_msg $green "$plugin plugin already installed"
fi
color_msg $blue "starting neo4j gremlin-server ..."
conf=$(realpath $gsd/conf/gremlin-server-neo4j.yaml)
$gsd/bin/gremlin-server.sh $conf
In the Neo4J section of http://wiki.bitplan.com/index.php/Gremlin_python#Connecting_to_Gremlin_enabled_graph_databases you'll find the explanation
Please not the check whether the ext directory contains the installation (see Stephen Mallette's question in a comment above).